A Kurt Cobain documentary might spell good news for fans of the Nirvana star but not for the musician’s daughter Frances Bean who is anxious about how he will be portrayed in the film.

The movie has been years in the making and Kurt’s 22-year old daughter Frances bean who was just 20 months when he died in 1994 is keen to protect her father’s artistry.

The film, directed by Brett Morgan, will pull together home movies and interviews with those who knew him best and document his life until his eventual demise.

Frances, 22, acted as executive producer, and Brett reveals she was never "a student of Kurt Cobain".

"However I think she feels that because she didn't know him, she doesn't bring the same history that others might. I think she felt very protective, but not of the myth, protective of Kurt as a man, as an artist, and that the art should not be polluted or commercialised," Brett explained to American GQ magazine.

"I don't think she had any interest in mythology. I think she felt that we needed to create an honest portrait of Kurt. And that was pretty much the extent of it. It was like, 'I want to make sure that we are dealing with him as an artist and not just a rock star and that it's honest.'"

The project has been years in the making, with numerous events halting production.

Aware that all of Kurt's belongings had been stashed in storage space, Brett often envisioned what the treasure trove would look like. When he finally got into the lock-up he was disappointed to find it was just an ordinary space filled with boxes, paintings and guitar cases.

"Upon further examination, Kurt left behind far more stuff than I would have at 27. But it wasn't the quantity, it was the quality. One box had a hundred and eight cassette tapes which translated into 200 plus hours of unheard audio. Another box had all of his journals, all of his writings from high school to the very end," he explained.

"Another box had thousands of 35-millimeter negatives - I had no idea that Kurt even took pictures."